题意：初始时有n个点(编号1到n)，每个点都没有父节点，然后依次执行下面两条命令：
思路：并查集+路径压缩维护距离值
#include <cstdio>
#include <queue>
#include <cstring>
#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <string>
#include <set>
#include <ctime>
#include <cmath>
#include <cctype>
using namespace std;
#define maxn 20010
#define LL long long
int cas=1,T;
int pre[maxn];
int dist[maxn];
int n;
void init()
{
for (int i = 0;i<=n;i++)
{
pre[i]=i;
dist[i]=0;
}
}
int Find(int x)
{
if (x!=pre[x])
{
int f = pre[x];
pre[x]=Find(pre[x]);
dist[x]+=dist[f];
return pre[x];
}
else
return x;
// return pre[x];
}
int main()
{
//freopen("in","r",stdin);
scanf("%d",&T);
while (T--)
{
scanf("%d",&n);
init();
char str[10];
while (scanf("%s",str))
{
int a,b;
if (str[0] == 'O')
break;
if (str[0] == 'I')
{
scanf("%d%d",&a,&b);
pre[a]=b;
dist[a]=abs(a-b)%1000;
}
if (str[0] == 'E')
{
scanf("%d",&a);
Find(a);
printf("%d\n",dist[a]);
}
}
}
//printf("time=%.3lf",(double)clock()/CLOCKS_PER_SEC);
return 0;
}
